Sir Ian McKellen is doing “very very well” following a fall from a West End stage on Monday, according to his understudy.

The veteran stage and screen actor, 85, was portraying John Falstaff in a production of Player Kings at the Noel Coward Theatre when he lost his footing in a fight scene and fell from the stage.

It was announced on Thursday that Sir Ian would not be performing again in London while he has physiotherapy and recuperates.

Understudy David Semark, 52, is taking his place as Falstaff.

Following his performance on Thursday evening, Semark told the PA news agency that Sir Ian had called him to let him know he would be playing the role.

Semark said: “The wonderful Sir Ian McKellen called me to tell me what was going on, which was amazing, and [he] has been incredibly supportive throughout the rehearsals.

“The first person I heard it from was Sir Ian.

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“We then had a discussion about the role. I have worked alongside him for months, so we get on, he’s a friend.”

He continued: “Obviously my first thought is for my friend, and the wonderful human being that is Sir Ian McKellen. He called me to tell me what was going on, which was amazing, and has been incredibly supportive throughout the rehearsals.

“I definitely couldn’t have had the courage to go on there tonight if I didn’t feel that he was behind me with me.

“But I am holding a place open for Sir Ian. I walk in the shadow of greatness….

“I’ve stolen 90% of what he does in that show shamelessly and tried to make it my own.

“It’s been an incredibly stressful couple of days.”

Asked how Sir Ian was doing following the fall, Semark replied: “He’s doing very very well.”

A post to the Player Kings account on X, formerly Twitter, on Thursday said: “David Semark will be playing the role of Sir John Falstaff for the final three scheduled performances of Player Kings at the Noel Coward Theatre in London while Ian McKellen recuperates following his fall on Monday 17 June.”

It added: “We look forward to Ian returning to the production, which begins a national tour in Bristol on Wednesday 3 July, before visiting Birmingham, Norwich and Newcastle.”